Creating a circle around your terrain
Many real-time strategy (RTS) games display distances (range attack, moving distance, sight, and so on) by drawing a circle around the selected unit. If the terrain is flat, this can be done simply by stretching a quad with the texture of a circle. If that’s not the case, the quad will most likely be clipped behind a hill or another piece of geometry. This recipe will show you how to create a shader that allows you to draw circles around an object of arbitrary complexity. If you want to be able to move or animate your circle, you will need both a shader and a C# script.
Getting ready
Despite working with every piece of geometry, this technique is oriented to terrains. Hence, the first step is setting up a terrain in Unity, but instead of using a model, we will create one within the Unity Editor:
- Let’s start by creating a new shader called
RadiusShaderand the respective material,RadiusMat. - Create a GameObject...
